Human activity is changing the Earth’s landscape at unparalleled rates. According to a recent report from World Wildlife Fund, these changes have had devastating impacts on animal populations around the world.

Last month, WWF released its 2018 Living Planet Report – a comprehensive study published every two years that examines the health of the planet and the state of global biodiversity. The report is a science-based analysis that relies on cutting-edge research and input from more than 50 experts in academia, policy, international development and conservation, who detail human impacts on the planet.

Using the Living Planet Index (LPI), a scale that describes the diversity and abundance of animals worldwide, this year’s report shows an average decline of 60 percent in global animal populations between the 1970s and 2014 – a number that confirms the toll of human activity on the environment.

“This report sounds a warning shot across our bow,” said WWF-US head Carter Roberts in a release. “Natural systems essential to our survival – forests, oceans, and rivers – remain in decline. Wildlife around the world continue to dwindle. It reminds us we need to change course. It’s time to balance our consumption with the needs of nature, and to protect the only planet that is our home.”

Understanding species loss and the Living Planet Index

The LPI measures the trends of more than 16,000 vertebrate populations representing 4,005 species, all facing varying threat levels and living conditions. It’s a weighted index, and species are ranked by their relative abundance and other factors, which contribute to the value in different ways. Although it’s not a census of all animals worldwide, the index provides us with an idea of how certain populations are faring across the globe.

Extinction risk alone is accelerating at dangerous speeds. Species extinction rates are now 100 to 1,000 higher than rates of loss prior to humans.

It’s also an average value: some populations lost more than 60 percent of individuals, while others lost fewer individuals. Although 60 percent of all animals on the planet have not been eliminated, the number is alarming nonetheless.

South and Central America, for example, have experienced an average 89 percent drop in vertebrate populations since 1970. Over the same period, North America and Greenland saw a 23 percent loss. Globally, freshwater species experienced particularly large declines – an average of 83 percent since 1970.

It’s complicated

Measuring biodiversity is complex, since every species plays a unique role in its ecosystem and responds to environmental changes in different ways. It can be hard to parse out all the sophisticated ways that natural ecosystems, and the organisms living in them, are connected. The report uses other biodiversity indicators to determine how animal distributions, community composition and extinction risks have changed to account for these complexities. All indicators show major declines or shifts in natural biodiversity.

Extinction risk alone is accelerating at dangerous speeds. Species extinction rates are now 100 to 1,000 higher than background rates (the rates of loss prior to human influence). With human impact, freshwater fish had the highest rate of extinction among vertebrates in the 20th century, largely a result of the effects of agriculture on freshwater systems. According to the report, 75 percent of all species that have gone extinct since 1500 AD have been harmed by overexploitation and agriculture.

This is only part of the damage. The report identifies five major threats to animals: habitat degradation and loss; overexploitation; invasive species and disease; pollution; and climate change. Habitat degradation and loss are the most common threats, accounting for nearly half of all threats to most major animal groups. Habitats are damaged or lost through unsustainable agriculture, residential and commercial development, logging and other human exploits.

Climate change has also had significant impacts on animal populations worldwide. By 2050, it’s expected that only 10 percent of the Earth’s land will remain untouched by humans.

What’s next?

Natural environments provide the building blocks for human development, and even global economies and financial markets require healthy environments to flourish. Ecosystem services account for an estimated US $125 trillion each year and declines in biodiversity could have substantial impacts on the economy and global financial markets.

If things remain unchanged, 90 percent of the world’s coral reefs – the most diverse marine habitats – could disappear by 2050. This not only has an impact on animal diversity, but also on the 200 million people that depend on coral to protect them against extreme weather events like storm surges and waves.

In 2017, 50 conservation scientists proposed a “Global Deal for Nature," calling for a more aggressive response to the extinction crisis by increasing habitat protection and restoration and large-scale conservation efforts. The deal aims to protect at least half of the Earth for nature conservation by 2050 and was seen as a crucial step toward achieving the UN’s 2030 Agenda for Sustainable Development and the Paris Agreement on climate change.

But as the human population grows, so will the demands for energy, land, food and water. Expanding urban landscapes will cause more pollution and environmental problems – without dramatic changes, our impacts on biodiversity will only hasten the rate of species loss.

The future is not entirely bleak, however. While the report points out what humans have done wrong, it also highlights what must be done to reverse the trends. The WWF is working with nearly 40 universities, as well as conservation and intergovernmental organizations, to include biodiversity in future systems modelling.

The report is a sobering reminder that “business as usual” is no longer an option. The time to think ahead, for both scientists and policy makers, is now.